This publication uses Master Specification CSI format, Section 03300 for Cast-in-place concrete to propose specification clauses and provides accompanying commentary as guidance. The discussion helps initiate specification revisions for sustainable and optimized concrete mixtures for improved performance. The publication evolved by a compilation of comments provided to actual specifications used for commercial projects. The commentary essentially emphasizes the fundamental concepts of specifications for ready mixed concrete addressed in industry standards published by ACI or ASTM International. Provisions of ACI 318-08, Building Code for Structural Concrete, as it relates to requirements concrete ingredient materials and mixtures, production and delivery are incorporated in this document. The guidance has been reviewed and approved by the NRMCA Research Engineering and Standards Committee.